4:10 gear install instructions

[Go Mifuni]

Was wondering if anyone could send me step-by-step instructions on changing out the gears. I've been putting it off for far too long due to the cost ($500?) and the wear issues with the axles (300a). Now thanks to a recent thread, I see we can get a bearing kit which relocates the bearings so we don't need to replace the axles. YAY! I have better than average mechanical skills and am very confident I can do this. I'm just a little intimidated. :confused:
I have the Ford gears from Dennis.
Feel free to PM me and thanx. :beer:

[fastblackmerc]

The easiest way to do it.


Buy the parts
Find someone that works on 8.8 Ford rear ends... usually the Mustang guys know who is good
Make appointment with said person / company
Keep that appointment
Pay the bill for the gear swap / setup
Follow the recommendations for proper break in of the new gears
Get a SCT tuner to correct the speedo.
Play with your new mod!

[Go Mifuni]

1. Bought the parts
2. Have a chip
3. Don't want to pay someone for something I can and want to do myself.
4. Looking forward to playing with the mod.
5. Thanks :D

[fastblackmerc]

Unless you've done gear swaps before (don't think you have since you asked how to do them here), don't attempt it. If the pattern isn't right you'll have all kinds of noise back there. I think the cost is between $200.00 & $300.00 and IMHO is worth every penny.

[VAmarauder03]

you have to have to be able to get a really good contact pattern between the pinion and ring otherwise noise will incur as stated above, you have to measure and shim the carrier correctly otherwise you can expect broken gears, if you get the pinion nut to tight and compress the crush washer(one time use) too far then expect premature bearing failure. Its really not hard to do once you know how to do it, but if you dont know how its hard to explain and attempt on your own for your first time. My advice would be go somewhere(cheaper than 500$ sounds like theyre gettin over on you)and ask if you can watch them install it and get a feel for how its done, if theyre cool they might answer any question about tightness and patterns that you may have.

[Stranger in the Black Sedan]

I just did this. Read my post, start to finish. It shows pictures of the problems I encountered along the way.

http://www.mercurymarauder.net/forums/showthread.php?t=36358

You will not be able to get the pattern perfect the first time. Expect wasting several days taking it in and out, driving the car, having some noise, etc. It can be done but it will take a lot more than just above average mechanical skills. There is a lot of subjectivity involved getting the pattern right, esp. the first time.

The easy way, is to use the dealer Rotunda pinion depth tool. It must be used with Ford genuine gears only (and FMS). Will not work with motive, richmond, etc. The tool is $1500+ but I got one on ebay for $250. Sorry but I can't loan it out, it's a delicate set of gage blocks. Without this tool, you will have lots of pressing in and out of the pinion ahead of you. You absolutely need a shop press, there is no way around that either.

If you were local I could do the gears for you, but I'm in VA.

[sabtaj1]

just barrow a dial indicator. That is what I used on mine, along with the bearing kit you mentioned. It really pretty easy, but I have done them before. I did mine on a lift in 1.5 hrs. including the bearing kit. The bearing kit works awsome. If your gonna have it apart you might as well do it regardless. Best of luck. Dial indicator (measures the backlash).

[Stranger in the Black Sedan]

You may get lucky and your stock shim is close enough for the new gears (only if you are using genuine Ford or FMS gears), then like sabtaj said its a piece of cake. My stock 0.028" shim was way off. I ended up with an 0.024 shim according to the Rotunda tool, and also according to visually checking the best pattern. For a lot of rears the stock shim should be close though. However, if you are unlucky and you assume the stock shim is fine, and you button the rear up and it whines, you get to take it apart again, and then you have to start trial and error checking pinion depth shims.

All Ford gears theoretically will set up at the same depth, assuming perfect gears. However, gear manufacturing tolerances will yield up to +/- 0.002 deviance from nominal pinion set up depth, according to Ford (I asked). Bearing tolerances should be near perfect, but they are not always. I found around 0.001 deviance from one Koyo high cap to another, in pinion depth. So if you get unlucky and the tolerances do not stack up in your favor, the stock shim may not put the ring and pinion in perfect contact like your factory gears were.

[RF Overlord]

Mike, you got some good advice ^^^. It's not an especially difficult job, but it also isn't really the type of job you want to attempt by yourself if you've never done it before, unless you have someone more experienced right there helping you. The right tools are essential, too, as VicsEvilBrother can attest.

Come on down the Cape and we'll "git 'er DONE!" for a lot less than $500.

[SC Cheesehead]

Unless you've done gear swaps before (don't think you have since you asked how to do them here), don't attempt it. If the pattern isn't right you'll have all kinds of noise back there. I think the cost is between $200.00 & $300.00 and IMHO is worth every penny.

^^^^^^^^^^^+2^^^^^^^^^^^ Suggest you purchase a diff. girdle as well and install it when you do the gear swap. Another $200 bucks, but worth it IMO.

SCCH

[Stranger in the Black Sedan]

It is worth every penny to have someone set gears up IF THEY KNOW WHAT THEY ARE DOING!! The Ford dealer near me set gears up on my car and they were horrible. Never again will I chance having someone else, who I pay, screw up gears. It was worth the learning curve for peace of mind. Just because the dealer (or any repair shop) has the tools doesn't mean the teach will do a good job. Find someone who has had gears set up near you, who is happy with the work.

[SC Cheesehead]

It is worth every penny to have someone set gears up IF THEY KNOW WHAT THEY ARE DOING!! The Ford dealer near me set gears up on my car and they were horrible. Never again will I chance having someone else, who I pay, screw up gears. It was worth the learning curve for peace of mind. Just because the dealer (or any repair shop) has the tools doesn't mean the teach will do a good job. Find someone who has had gears set up near you, who is happy with the work.

VEB,

Yeah, I hear you on that one. I had frdwrnch do mine, and he did a top-notch job. Anyone near the Charlotte, NC area looking for a gear install (or any other MM work for that matter) ought to look him up. He's the only guy (outside of me) that does any work on my Blue.

SCCH

[fastblackmerc]

^^^^^^^^^^^+2^^^^^^^^^^^ Suggest you purchase a diff. girdle as well and install it when you do the gear swap. Another $200 bucks, but worth it IMO.

SCCH

Yes, the stud girdle & the hardened stud kit from Ford (to replace the bolts for the carrier bearings, usually less than $30.00). Both cheap insurance.